<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>固定定位</title>
<!--    以HTML 浏览器窗口固定-->
    <style>
        .fu {
            background-color: yellow;
            overflow: hidden;
        }

        .fu > div {
            width: 100px;
            height: 100px;
            border: 3px solid red;

        }

        .z1 {
            background-color: red;
        }

        .z2 {
            background-color: blue;
            position: fixed;
            right: 200px;

        }

        .z3 {
            background-color: green;
        }
    </style>
</head>
<body>
<div class="fu">
    <div class="z1"></div>
    <div class="z2"></div>
    <div class="z3"></div>
</div>
</body>
</html>